Bit Retention Device

ABSTRACT

A bit retention device includes a shaft having a sidewall defining a hexagonal cavity extending from a first end thereof and a ball groove extending through the sidewall and communicating with the hexagonal cavity. A ball is disposed in the ball groove and a ball spring engages the ball and biases the ball toward the first end. An actuator sleeve surrounding the shaft includes an internal ramp engaging the ball. A spring biased plunger assembly is disposed in the bore for biasing a bit received in the bore in a direction toward the insertion end.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 12/394,426, filed on Feb. 27, 2009, and acontinuation-in-part application of U.S. patent application Ser. No.12/769,981, filed on Apr. 29, 2010 which claims priority to U.S.Provisional Application No. 61/175,583, filed on May 5, 2009. The entiredisclosures of the above applications are incorporated herein byreference.

FIELD

The present disclosure relates to power or hand tool bit retentiondevices, variously known as “auxiliary chucks,” “chucks,” “adapters,” or“bit holders” for removably receiving tool bits, such as fastenerdrivers, drill bits, or the like, for rotation therewith when the powertool is actuated or the hand tool is manually rotated. Moreparticularly, the present disclosure relates to a bit retention deviceconfigured for rapid and easy insertion and removal of a bit.

BACKGROUND AND SUMMARY

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Bit retention devices for power and hand tools have become increasinglycommon, especially as the need and desirability of wider versatility andthe use of power tools and hand tools has increased. Such bit retentiondevices allow the hand or power tool to be used with any of a number ofinterchangeable bits. This, in turn, has resulted in demands for greaterspeed, convenience, and ease for insertion and removal of tool bits fromthe bit retention device.

In one exemplary type of conventional bit retention device, one or moredetent balls are positioned within a hollow, barrel-shaped tool bitholder body and are resiliently biased into engagement with acircumferentially-extending groove or recess on the shank of the toolbit. Although this basic design has performed well, such conventionalquick-release bit retention devices frequently require the operator toactuate a sleeve, collar, or other component part during both theinsertion and the removal of the tool bit.

Accordingly, the present disclosure seeks to provide a bit retentiondevice that requires the operator to actuate its components only upontool bit removal. A “snap-in” type of bit retention device is providedfor a drill, driver, or other rotary hand or power tool. The bitretention device includes a shaft having a sidewall defining a hexagonalcavity extending from a first end thereof and a ball groove extendingthrough the sidewall and communicating with the hexagonal cavity. A ballis disposed in the ball groove and a ball spring engages the ball andbiases the ball toward the first end. An actuator sleeve surrounds theshaft and includes an internal ramp engaging the ball. The internal rampincludes a shallow ramp portion having a first angle of inclination withrespect to a center axis of the shaft and a steep portion having asecond angle of inclination with respect to the center axis of the shaftthat is greater than the first angle of inclination. The steep portionincludes a smaller diameter than the shallow ramp portion.

According to another aspect, the present disclosure provides a bitretention device, wherein a spring biased plunger biases the bit out ofengagement with the ball when the actuator sleeve is pulled forward.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a longitudinal cross-sectional view of a bit retention deviceaccording to the principles of the present disclosure;

FIG. 2 is an exploded perspective view of the bit retention device shownin FIG. 1;

FIG. 3 is an exploded perspective view of the plunger sub-assemblyaccording to the principles of the present disclosure;

FIG. 4 is an enlarged cross-sectional view of the bit retention deviceshown in FIG. 1 and illustrating the details of the ramp on the interiorsurface of the actuation sleeve, according to the principles of thepresent disclosure;

FIG. 5 is a cross-sectional view of the bit holder device shown with thesleeve pulled in a forward release position for allowing the removal ofthe tool bit;

FIG. 6 is a cross-sectional view of the bit holder device with a toolbit being inserted into the bit holder according to the principles ofthe present disclosure;

FIG. 7 is a cross-sectional view of the bit holder device with the toolbit being pressed into the bit retention device so that the ball is slidrearward along the ramp portion of the actuator sleeve;

FIG. 8 is a cross-sectional view of the bit retention device with thebit inserted further within the hexagonal cavity prior to the ball beingreceived in the ball groove of the screwdriver bit;

FIG. 9 illustrates a cross-sectional view of the bit retention devicehaving a “bit tip”-type bit being inserted therein according to theprinciples of the present disclosure;

FIG. 10 illustrates the “bit tip”-type being further inserted into thebit retention device with the ball being pushed rearward along the rampon the interior surface of the actuator sleeve;

FIG. 11 is a cross-sectional view showing the engagement of a “bittip”-type screwdriver bit fully inserted into the bit retention deviceaccording to the principles of the present disclosure;

FIG. 12 is a perspective view of a nose magnet applied to the bitretention device according to the principles of the present disclosure;

FIG. 13 is a cross-sectional view of the nose magnet applied to a bitretention device according to the principles of the present disclosure;

FIG. 14 is a perspective view of a non-marring nose cover applied to thebit retention device of the present disclosure;

FIG. 15 is a partial cross-sectional view of the non-marring nose coverapplied to a bit retention device according to the principles of thepresent disclosure;

FIG. 16 is a cross-sectional view of a combined nose magnet and nosecover assembly according to the principles of the present disclosure;

FIG. 17 is a perspective view of the bit retention mechanism employing aball with the forward bearing removed for illustrative purposes;

FIG. 18 is a detailed partial cross-sectional view of the power tool ofFIG. 17 shown in a disengaged position;

FIG. 19 is a detailed partial cross-sectional view of the power tool ofFIG. 17 illustrating a bit being inserted therein;

FIG. 20 is a detailed partial cross-sectional view of the power tool ofFIG. 17 illustrating a bit fully inserted therein;

FIG. 21 is a detailed partial cross-sectional view of the power tool ofFIG. 17 illustrating a bit being released therefrom;

FIG. 22 is a detailed partial cross-sectional view of the power tool ofFIG. 17 illustrating a 1″ bit being inserted therein;

FIG. 23 is a detailed partial cross-sectional view of the power tool ofFIG. 17 illustrating a 1″ bit fully inserted therein;

FIG. 24 is a detailed partial cross-sectional view of the power tool ofFIG. 17 illustrating a 1″ bit being released therefrom;

FIG. 25 is an exploded perspective view of a further bit retentiondevice according to the principles of the present disclosure;

FIG. 26 is an assembled partial cut-away perspective view of the bitretention device shown in FIG. 25; and

FIG. 27 is a perspective view of the bit retention device shown in FIG.25 with the actuator sleeve removed for illustrative purposes.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on”, “engaged to”,“connected to” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto”, “directly connected to” or “directly coupled to” another element orlayer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.).

Spatially relative terms, such as “inner,” “outer,” “forward,”“rearward,” “lower,” “above,” “upper” and the like, may be used hereinfor ease of description to describe one element or feature'srelationship to another element(s) or feature(s) as illustrated in thefigures.

With reference to the accompanying Figures, the bit retention device 10according to the principles of the present disclosure will now bedescribed. The bit retention device 10 includes a shaft 12 defining apolygonal cavity 14 for receiving a tool bit or the like 16. Thepolygonal cavity 14 can be hexagonal. A plunger sub-assembly 18 isreceived in a bore 20 extending from the polygonal cavity 14. Anactuator sleeve 22 is disposed around a first end 24 of the shaft 12 andengages a ball 26 that is received in a ball groove 28 of the shaft 12.A ball spring 30 is disposed in the ball groove 28 and biases the ball26 against an interior ramp 32 of the actuator sleeve 22. A ball springretainer sleeve 34 surrounds the shaft 12 and retains a second end ofthe ball spring 30 within the ball groove 28.

An actuator spring 36 biases the actuator sleeve 22 in a rearwarddirection relative to the first end 24 of the shaft 12. A retainer clip40 is received in a recessed groove 42 in the first end 24 of the shaft12 and disposed against a forward end of the actuator spring 36. Asecond end of the actuator spring 36 is received against an interiorshoulder portion 44 of the actuator sleeve 22 in order to bias theactuator sleeve 22 in a rearward direction relative to the first end 24of the shaft 12. The actuator sleeve 22 includes a rear shoulder portion46 that can be located adjacent to the ramp 32 and can engage the ballspring retainer sleeve 34 at a forward end thereof to limit rearwardmovement of the actuator sleeve 22. The actuator sleeve 22 can include arearwardly extending cylindrical guide portion 48 that engages an outersurface of the ball spring retainer sleeve 34 for sliding engagementtherewith. The ball spring retainer sleeve 34 can include an internaldiameter portion 50 that snuggly receives the shaft 12 therein.

With reference to FIG. 3, the plunger assembly 18 can include a springseat 54 that is adapted to be press fit into a receiving groove 56within the bore 20 as illustrated in FIG. 1. The spring seat 54 includesa center post 58 which is adapted to receive a plunger spring 68thereon. A plunger member 66 is disposed against a forward end of theplunger spring 68.

The plunger member 66 has a recessed cavity 60 for receiving the plungerspring 68. The plunger sub-assembly 18 is inserted into the rear end ofthe bore 20 so that the forward end of the spring 68 engages the plungermember 66. The spring seat 54 is inserted into the bore 20 until thespring seat 54 engages the receiving groove 56 within the bore 20. Theplunger member 66 is designed to slide freely within the bore 20 whilethe spring 68 biases the plunger member 66 toward the first end 24 ofshaft 12.

With reference to FIG. 4, the ramp 32 of the actuator sleeve 22 will nowbe described. The ramp 32 includes a shallow ramp portion 32A and asteep ramp portion 32B. The shallow ramp portion 32A has a first angleof inclination α relative to the central axis X of the shaft 12 that canbe between 5 and 15 degrees, and more particularly about 10 degrees. Thesteep ramp portion 32B has a second angle of inclination β relative tothe central axis X that is larger than the angle of inclination α of theshallow ramp portion 32A. The steep ramp portion 32B can have an angleof inclination β relative to the central axis X that is between 13 and23 degrees, and more particularly about 18 degrees. The ramp portion 32can further include a third ramp portion 32C that is generally parallelto the axis X of the shaft 12 thereby defining a cylindrical wallportion thereon. The angles and positions of ramp portions 32A and 32Bare such that they allow the ball to pass the corner of the groove 70 ofthe power bit 16. In other words, the dimensions from the corner of thegroove to ramp surfaces 32A and 32B are greater than the ball diameterwhen the sleeve is seated in its rearward position. The spring 30 urgesthe ball 26 past the corner of the groove in the power bit to its fullyforward position. The ramp surface 32B and surface 32C direct the ballinto greater engagement with the groove 70 in the power bit 16.

During assembly, the plunger sub-assembly 18 is inserted into the bore20 until the spring seat 54 is disposed within the receiving groove 56within the bore 20. The ball spring retaining sleeve 34 is then slidover the shaft 12, and the ball spring 30 and ball 26 are inserted intothe ball groove 28 so that the ball spring retaining sleeve 34 overlapsthe rear end of the ball spring 30 in order to retain the ball spring 30within the ball groove 28. The actuator sleeve 22 is then inserted ontothe end of the shaft 12 and the actuator spring 36 is slid over the endof the shaft 12 inside of the actuator sleeve 22 so that the actuatorspring 36 abuts against the shoulder portion 44 of the actuator sleeve22. The retaining clip 40 is then installed on the shaft 12 so that theretainer clip 40 is received in the recessed groove 42 at the first end24 of the shaft 12.

It should be noted that the shaft 12 can be designed to be permanentlyinstalled on a rotating shaft of a power tool or can alternatively bedesigned to be removably engaged from a power tool or a hand tool. Thebit retention device 10 can be utilized for retaining various types ofhexagonal bits such as screwdriver bits and drill bits.

A common form of bit is referred to as a “power bit” which includes ahexagonal shank portion having an annular radiused groove 70 thereinthat is designed to receive a ball or other retaining member of aretention device. An exemplary “power bit”-type bit is illustrated inFIGS. 1, 2, and 5-8. When the bit retention device 10 of the presentdisclosure is utilized for retaining a power bit, the ball 26 isreceived in the annular groove 70 of the bit 16 as illustrated inFIG. 1. In this position, the ramp portion 32C retains the ball withinthe annular groove 70 of the bit 16. In order to release the bit 16 fromthe retention device 10, the actuator sleeve 22 is pulled in a forwarddirection as illustrated in FIG. 5 so that the ball 26 is able to moveradially outward out of the annular groove 70 and the plunger assembly18 pushes the bit forward so that the ball groove 70 is no longer inalignment with the ball 26. The sleeve 22 can then be released and thebit 16 can be extracted with the same hand, thus making it a simple onehand operation to remove the bit 16.

In order to insert a bit into the bit retention device, the bit isinserted into the polygonal cavity 14, as illustrated in FIG. 6, untilthe end of the bit 16 engages the ball 26, as shown in FIG. 6. The bit16 is then pressed further inward so that the ball 26 presses againstthe spring 30 and moves rearward in the ball groove 28 and upward alongthe ramp 32 of the actuator sleeve 22. Once the ball 26 moves far enoughalong the ramp 32, the ball 26 rides along a vertex of the hexagonalsurface of the bit 16. The bit 16 then presses against the plunger 66and presses the plunger 66 rearward as illustrated in FIG. 8. The bit 16is then pressed further inwards to its fully locked position asillustrated in FIG. 1.

Another type of bit is often referred to as a “bit tip” as illustratedby references numeral 80 in FIGS. 9-11. For installation of a bit tip 80in the bit retention device 10, the bit tip 80 is inserted into thepolygonal cavity 14 as illustrated in FIG. 9. As the bit tip 80 engagesthe ball 26, the ball is pressed rearward, compressing the ball spring30 and the ball is caused to move relative to the ramp 32 so that theball 26 can move radially outward as it traverses the ramp 32, asillustrated in FIG. 10. As the ball 26 moves radially outward to asufficient extent, the bit tip 80 is then able to move freely inwardagainst the biasing force of the plunger assembly 18. The bit tip 80 isthen pressed inward to its full extent as illustrated in FIG. 11.

In the fully inserted position, the ball 26 is biased against theshallow ramp portion 32A of the ramp 32 of the actuator sleeve 22. Thesmaller angle of inclination a of the shallow ramp portion 32A providesa radial force against the ball 26 that is sufficient for retaining thebit tip 80 within the bit retention device 10 without the ball 26 havingto engage any recess on the bit tip 80.

In order to release the bit tip 80 from the bit retention device 10, theactuator sleeve 22 is pulled in a forward direction and the plunger 18biases the bit tip forward a sufficient amount for the bit tip 80 to beremoved by the user. The use of a ramp 32 having a shallow ramp portion32A and a steep ramp portion 32B allows the bit retention device 10 tobe utilized with various kinds of tool bits wherein the ball 26 is ableto be received in an annular groove of a “power bit”-type bit with rampportion 32B causing the ball 26 to move radially inward to a greaterextent than the shallow ramp portion 32A so that the ball is properlyreceived within the ball groove 70 of the power bit. The greater angleof inclination of the steep ramp portion 32B allows the ramp 32 to beshorter and therefore the actuator sleeve 22 can be more compact. Theshallow ramp portion 32A provides a sufficient radial inward force toretain a “bit tip”-type bit within the bit retention device 10 withoutthe ball 26 needing to engage a recess on the bit.

The spring biased ball 26 allows a user to insert a bit 16 into the bitretention device 10 without having to use a second hand tosimultaneously engage the actuator sleeve 22. Instead, the user can holdthe tool with one hand and insert the bit 16, 80 into the bit retentiondevice with the other hand. In order to release the bit 16, 80 from thebit retention device 10, the actuator sleeve 22 can then be pulledforward and the plunger assembly 18 presses the bit 16, 80 forward asufficient amount so that the sleeve 22 can be released and the bit 16,80 can be grasped by the same hand and removed from the bit retentiondevice 10, thus making it a one-hand operation to remove the bit 16. Theplunger spring 68 can be provided with a sufficient spring force tocause the bit 16, 80 to be moved forward upon activation of the actuatorsleeve 22, but not too strong to eject the bit 16, 80 from the bitretention device.

As shown in FIGS. 12-13, a nose magnet 90 can have an annular shape witha central aperture 92 magnet 90 has concentric ribs 94 that conform tothe front of the shaft 12 and sleeve 22 to locate the magnet 90 and holdit concentric to the bit retention device 10. The magnet holds to theshaft in sleeve and holds a fastener in engagement with the bit 16because the nose magnet 90 is external to the bit retention device 10,it does not attract metal debris inside the bit retaining device 10.Furthermore, the magnet 90 can be adhered to the actuator sleeve orotherwise connected thereto so that the magnet does not become dislodgedfrom the bit retention device 10. Alternatively, the nose magnet 90 canbe removably attached under its magnetic traction to the actuator sleeve22 so that it can be easily removed and reinserted by the user, asdesired.

With reference to FIGS. 14-15, a non-marring nose cover 100 can bedisposed over the bit retention device 10. The non-marring nose cover100 can be made of a plastic or elastomeric material and can be formedsuch that it can be slipped over the actuator sleeve 22 and retainsitself in place with a slight interference or wrap around portion 102that wraps around the proximal end of the actuator sleeve 22. The nosecover 100 can further include a distal end portion that wraps over theend portion of the bit retention device 10 with a central aperture 106for receiving a bit 16 therein. The non-marring nose cover 100 preventsthe knurled metal sleeve 22 from marring a work material. The forwardportion 104 reduces or eliminates infiltration of dust and debris intothe bit retention device allowing it to operate more smoothly for alonger period of time. The aperture 106 in the forward portion 104 canfit snugly around the bit 16.

As shown in FIG. 16, the bit retention device 10 can further be providedwith an over-molded magnetic nose cover 110. The over-molded magneticnose cover 110 can include a nose magnet 90 constructed generally asdescribed above. A plastic cover 112 can be over-molded on the nosemagnet 90 or alternatively, the nose magnet 90 can be inserted into thecover 112. The cover 112 can be made of plastic or elastomer and isdesigned to prevent the knurled metal sleeve 22 from marring the workmaterial. A slight interference between the cover 112 and the sleeve 22may retain the cover onto the shaft or, alternatively, a wrap aroundportion or adhesives can be utilized for securing the cover 112 onto theactuator sleeve 22. In assembled condition as illustrated in FIG. 16,the nose magnet 90 will attract a fastener to the bit 16 hold thefastener in place. Furthermore, the cover portion 112 protects the workpiece from being marred while a fastener is being inserted. It should benoted that the magnet 90 may also retain the cover onto the shaft toprovide a cover 112 and magnet 90 that can be easily removed as desiredby the user.

With reference to FIGS. 17-24, a further embodiment of a power tool 510having an integrated bit retention mechanism 512 will now be described.According to the embodiment as shown in FIG. 17, an actuator button 514is disposed in a position forward of the trigger 18 and is pulled in agenerally axial direction to release a bit B from the bit retentionmechanism 512. With reference to FIG. 51, the actuator button 514 isdisposed against a return spring 516 which biases the actuator button514 in a forward direction. The actuator button 514 is connected to ashift fork or member 518 which is slidably received in a portion of thehousing 14 of a power tool. It should be appreciated that shift member518 can comprise any mechanical interconnection system, includinglinkages, gearing, or other mechanical actuators. The shift member 518includes an arm portion 519 connected to the actuator button 514. Theshift member 518 includes a pair of forward arms or enclosed ring 520which are/is received against a radially extending flange 522 of asleeve member 524.

The sleeve member 524 has a central aperture 526 for being slidablyreceived on a spindle 528. The spindle 528 includes a polygonal cavity530 adapted for receiving a tool bit B therein. The spindle 528 alsoincludes a ball slot 532 that communicates with the polygonal cavity530. A ball 534 is received in the ball slot 532 of the spindle 528 andis movable along the ball slot 532 to engage and disengage a bitreceived within the polygonal cavity 530. The ball 534 engages andremains engaged against a stop member 536 extending from an innersurface of the central aperture 526 of sleeve member 524. In this way,stop member 536 can cooperate, as will be described, with other membersto engage ball 534 with a retaining feature formed on bit B. However,during insertion and commanded release, ball 534 is permitted to move toa position adjacent stop member 536 to permit disengagement of ball 534from the retaining feature formed on bit B.

A compression spring 538 is disposed against the ball 534 at a forwardend of the spring and against a shoulder portion 540 of the spindle 528at a rearward position, such that ball 534 is generally aligned with andengaging stop member 536. The shift member 518 is operable in responseto actuation of the actuator button 514 to slide the sleeve member 524in a rearward direction. In the case of a longer bit B having a ballgroove B1, the rearward or aft translation of sleeve member 524 and stopmember 536 permits ball 534 to move radially outward to a positionforward of stop member 536 (see FIG. 21) for disengaging the bit Breceived in the polygonal cavity 530. However, in the case of a shorterbit B having a ball chamfer B2 that does not permit ball 534 to ridebetween stop member 536 and ball chamfer B2 (see FIG. 24), the rearwardor aft translation of sleeve member 524 and stop member 536 causes ball534 to be moved aft to a disengaged position with ball chamfer B2 fordisengaging the bit B received in the polygonal cavity 530.

When the actuator button 514 is released, the return spring 516 biasesthe actuator button 514 to its forward position along with the shiftmember 518 thereby allowing the sleeve member 524 to move to its forwardposition. The stop member 536, having ramping surfaces 537, is thentranslated into a position radially adjacent ball 534, thereby urgingball 534 radially inward to polygonal cavity 530 (and into engagementwith bit B, if present). Additionally, to some extent, compressionspring 538 biases ball 534 forward against ramping surface 537 of stopmember 536 causing ball 534 to translate along the ramping surface in aradially inward direction.

The insertion of a bit B into the bit retention mechanism 512 is againby “drop-in-to-load” insertion wherein the bit B pushes the ball 534rearward against the biasing force of compression spring 538 to at leasta position aft of stop member 536 (see FIGS. 19 and 22), therebypermitting ball 534 to move radially outward along the ball slot 532until the bit B can be fully inserted. Once bit B is inserted asufficient distance, ball 534, under the forward biasing force ofcompression spring 538, is caused to engage ball groove B1 or ballchamfer B2 of bit B (see FIGS. 20 and 23, respectively).

With reference to FIGS. 18-24, the spindle 528 is supported at a forwardend by a forward bearing 542 and at a rearward end by a rearward bearing544. The entire bit retention mechanism 512 can be disposed axiallybetween the forward end of the forward bearing set 542 and the forwardend of the rearward bearing set 544. The bit retention mechanism 512 canalso be completely disposed within the housing 14 wherein the nose cover550 defines a portion of the housing 14.

A fixed nose cover 550 is supported over a forward end of the forwardhousing portion 14 a and conceals the shift member 518.

With reference to FIGS. 25-27, a bit retention device 110, according toa further embodiment of the present disclosure, will now be described.The bit retention device 110 includes a shaft 112 having a sidewall 113defining a polygonal cavity 114 for receiving a tool bit or the like 16.The polygonal cavity 114 can be hexagonal. A plunger sub-assembly 118 isreceived in a bore extending from the polygonal cavity 114 within theshaft 112. An actuator sleeve 122 is disposed around a first end 124 ofthe shaft 112 and engages a retainer 126 that is received in a grooveopening 128 of the sidewall 113 of the shaft 112. A retainer spring 130substantially surrounds the shaft 112 and biases the retainer 126 in aforward direction (best shown in FIG. 26). The retainer spring 130 canbe a helical compression spring having a helix portion 130 a and endingat a bend portion 130 c that transitions to an inwardly projectingportion 130 b that is received at least partially in the groove opening128 (best shown in FIGS. 26 and 27) to bias the retainer 126 in aforward direction toward the front end 124 of the shaft 112. Theinwardly projecting portion 130 b defines a retainer engaging portionthat can have a shape complementary to the shape of the retainer element126. The retainer 126 can be in the form of a ball, as shown, or canhave other forms such as a cylindrical roller or a pin. The shape of theinwardly projecting portion 130 b can be curvilinear, includingU-shaped, V-shaped, or otherwise formed to fit into the groove opening128 and engage the retainer 126. A rearward portion of the retainerspring 130 can be disposed against a forward facing shoulder 112 a ofthe shaft 112. The shoulder 112 a can be integrally formed with theshaft 112 or separately formed from a member received on the shaft 112.

An actuator spring 136 biases the actuator sleeve 122 in a rearwarddirection relative to the first end 124 of the shaft 112. A retainerclip 140 is received in a recessed groove 142 in the first end 124 ofthe shaft 112 for supporting a washer 144 against a forward end of theactuator spring 136. A second end of the actuator spring 136 is receivedagainst an interior shoulder portion 145 (best shown in FIG. 26) of theactuator sleeve 122 in order to bias the actuator sleeve 122 in arearward direction relative to the first end 124 of the shaft 112. Theactuator sleeve 122 includes a rear shoulder portion 146 (best shown inFIG. 26) that can be located adjacent to the forward facing shoulder 112a of the shaft 112 to limit rearward movement of the actuator sleeve122. The actuator sleeve 122 can include a rearwardly extendingcylindrical guide portion 148 that engages an outer surface 112 b of theshaft 112 rearward of the shoulder 112 a for sliding engagementtherewith.

The plunger sub-assembly 118 can include a spring seat 154 that isadapted to be inserted within a rear portion of the bore of the shaft112. The spring seat 154 can include a center post 158 which is adaptedto receive a plunger spring 168 thereon. A plunger member 166 isdisposed against a forward end of the plunger spring 168. The springseat 154 can be retained in the bore by an internal retention ring 170received in an internal groove within the bore.

The plunger member 166 can have a recessed cavity for receiving theplunger spring 168. The plunger sub-assembly 118 is inserted into therear end of the bore in the shaft 112 so that the forward end of thespring 168 engages the plunger member 166. The spring seat 154 andretention ring 170 are inserted into the bore until the retention ring170 engages the internal groove within the bore. The plunger member 166is designed to slide freely within the bore while the spring 168 biasesthe plunger member 166 toward the first end 124 of shaft 112.

The ramp 132 (FIG. 26) of the actuator sleeve 122 can optionally includea shallow ramp portion 32A and a steep ramp portion 32B, as discussedabove with reference to the embodiment disclosed in FIG. 4 and istherefore not described in further detail herein.

During assembly, the retainer spring 130 is slid over the shaft 112 sothat it engages the shoulder 112 a and the retainer, such as a ball 126,is inserted into the groove opening 128 so that the inwardly projectingportion 130 b of the retainer spring is received in the groove opening128 and engages the ball or other retainer 126 to bias the ball in aforward direction. The actuator sleeve 122 is then inserted onto the endof the shaft 112 and the actuator spring 136 is slid over the end of theshaft 112 inside of the actuator sleeve 122 so that the actuator spring136 abuts against the shoulder portion 145 of the actuator sleeve 122.The retaining clip 140 and washer 144 are then installed on the shaft112 so that the retainer clip 140 is received in the recessed groove 142at the first end 124 of the shaft 112 and the washer 144 engages thefront end of the actuator spring 136.

It should be noted that the shaft 112 can be designed to be permanentlyinstalled on a rotating shaft of a power tool or can alternatively bedesigned to be removably engaged from a power tool or a hand tool. Thebit retention device 110 can be utilized for retaining various types ofhexagonal or other polygonal shaped bits such as screwdriver bits anddrill bits.

A common form of bit includes a hexagonal shank portion having anannular radiused groove or a small notch therein that is designed toreceive a ball or other retaining member of a retention device. When thebit retention device 110 of the present disclosure is utilized forretaining a bit, the ball 126 is received in an annular groove, thesmall notch, another recess, or against the surface of the bit 16. Forexample, when used with a bit 16 having an annular groove 70, the rampportion 132 retains the ball within the annular groove 70. In order torelease the bit 16 from the retention device 110, the actuator sleeve122 is pulled in a forward direction so that the ball or other retainerelement 126 is able to move radially outward out of the annular groove70 and the plunger assembly 118 pushes the bit forward so that the ballgroove 70 is no longer in alignment with the ball 126. The sleeve 122can then be released and the bit 16 can be extracted with the same hand,thus making it a simple one hand operation to remove the bit 16.

In order to insert a bit into the bit retention device 110, the bit isinserted into the polygonal cavity 114, until the end of the bit 16engages the ball 126. The bit 16 is then pressed further inward so thatthe ball 126 presses against the retainer spring 130 and moves rearwardin the groove opening 128 and upward along the ramp 132 of the actuatorsleeve 122. Once the ball 126 moves far enough along the ramp 132, theball 126 rides along a vertex of the hexagonal surface of the bit 16.The bit 16 then presses against the plunger 166 and presses the plunger166 rearward. The bit 16 is then pressed further inwards to its fullylocked position.

In order to release the bit from the bit retention device 110, theactuator sleeve 122 is pulled in a forward direction and the plunger 118biases the bit forward a sufficient amount for the bit to be removed bythe user.

The spring biased ball or other retainer 126 allows a user to insert abit 16 into the bit retention device 110 without having to use a secondhand to simultaneously engage the actuator sleeve 122 and pull itforward. Instead, the user can hold the tool with one hand and insertthe bit 16, 80 (FIGS. 1 and 9) into the bit retention device 110 withthe other hand. In order to release the bit 16, 80 from the bitretention device 110, the actuator sleeve 122 can then be pulled forwardand the plunger assembly 118 presses the bit 16, 80 forward a sufficientamount so that the sleeve 122 can be released and the bit 16, 80 can begrasped by the same hand and removed from the bit retention device 110,thus making it a one-hand operation to remove the bit 16. The plungerspring 168 can be provided with a sufficient spring force to cause thebit 16, 80 to be moved forward upon activation of the actuator sleeve122, but not too strong to eject the bit 16, 80 from the bit retentiondevice 110.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention. Individual elements or features ofa particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the invention, and all such modificationsare intended to be included within the scope of the invention.

1. A bit retention device, comprising: a shaft having a front end, arear end, a sidewall defining a bit receiving cavity extending from thefront end toward the rear end, and an opening extending through thesidewall and communicating with the bit receiving cavity; a ballreceived in the opening; a ball spring substantially surrounding theshaft, and having an inward projecting portion that is received at leastpartially in the opening to bias the ball toward the front end; and anactuator sleeve substantially surrounding the shaft and having aninternal wall that engages the ball, wherein the actuator sleeve ismoveable between a first position in which the internal wall pushes theball radially inward toward the cavity, and a second position in whichthe internal wall allows the ball to move radially outward from thecavity.
 2. The bit retention device of claim 1, wherein the ball springcomprises a helical compression spring.
 3. The bit retention device ofclaim 2, wherein the inward projecting portion of the ball springextends radially inward of a helix defined by the helical compressionspring.
 4. The bit retention device of claim 2, wherein the inwardprojecting portion comprises a non-helical portion of the helicalcompression spring.
 5. The bit retention device of claim 3, wherein thehelical compression spring comprises a bend that extends radiallyinwardly away from the helix of the helical compression spring andtransitions to the inward projecting portion.
 6. The bit retentiondevice of claim 2, wherein the inward projecting portion comprises acurvilinear portion of the ball spring.
 7. The bit retention device ofclaim 1, wherein the ball is seated against the inward projectingportion of the ball spring.
 8. The bit retention device of claim 1,wherein the second position is frontward of the first position.
 9. Thebit retention device of claim 1, further comprising an actuator springbiasing the actuator sleeve toward the first position.
 10. The bitretention device of claim 1, wherein the actuator sleeve has an internalramp surface that engages the ball, the ramp surface having a firstportion at a first ramp angle and a second portion at a different,second ramp angle.
 11. The bit retention device of claim 1, furthercomprising a power tool housing receiving the shaft, the power toolhousing including an external switch coupled to the actuator, whereinactuation of the external switch moves the actuator between the firstand second positions.
 12. A bit retention device, comprising: a shafthaving a front end, a rear end, a sidewall defining a bit receivingcavity extending from the front end toward the rear end, and an openingextending through the sidewall and communicating with the bit receivingcavity; a retaining element received in the opening; a retaining springsubstantially surrounding the shaft, and having an inward projectingportion that is received at least partially in the opening to bias theretaining element toward the first end; and an actuator sleevesubstantially surrounding the shaft, the actuator sleeve moveablebetween a first position closer to the rear end and a second positioncloser to the front end, wherein, in the first position the retainingelement is caused to engage a bit received in the cavity, and in thesecond position the retaining element is allowed to disengage from a bitreceived in the cavity.
 13. The bit retention device of claim 12,wherein the retaining spring comprises a helical compression spring. 14.The bit retention device of claim 13, wherein the inward projectingportion of the retaining spring extends radially inward of a helixdefined by the helical compression spring.
 15. The bit retention deviceof claim 13, wherein the inward projecting portion comprises anon-helical portion of the helical compression spring.
 16. The bitretention device of claim 14, wherein the helical compression springcomprises a bend that extends radially inwardly away from the helix ofthe helical compression spring and transitions to the inward projectingportion.
 17. The bit retention device of claim 13, wherein the inwardprojecting portion comprises a curvilinear portion of the retainingspring.
 18. The bit retention device of claim 12, further comprising anactuator spring biasing the actuator sleeve toward the first position.19. The bit retention device of claim 12, wherein the retainer is seatedagainst the inward projecting portion of the retainer spring.
 20. Thebit retention device of claim 12, wherein the actuator sleeve has aninternal ramp surface that engages the retaining element, the rampsurface having a first portion at a first ramp angle and a secondportion at a different, second ramp angle.